Playback apparatus, electronic camera apparatus, function expansion apparatus for electronic camera apparatus, control method for electronic camera apparatus, control method for image communication apparatus, and medium for providing control program

ABSTRACT

In order to provide a convenient digital camera which eliminates the necessity to designate a printer to print in advance and can print image data obtained by photography by reliably transmitting it to a printer existing on a radio network with simple operation, the digital camera performs control such that the classifications of electronic devices constituting the radio network are acquired through a radio communication circuit unit, and if one printer exists on the radio network, the image data is transmitted to the printer, and if a plurality of printers exist on the radio network, the image data is transmitted to a selected one of the printers.

This application is a divisional of U.S. patent application Ser. No.10/022,507, filed on Dec. 20, 2001, now U.S. Pat. No. 6,947,163.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic camera such as a digitalcamera and, more particularly, to an electronic camera apparatus,playback apparatus (reproduction apparatus), and the like, whichconstitute a radio network and has a radio communication function ofcommunicating data.

2. Related Background Art

Recently, digital cameras designed to convert image signals obtained byphotography into digital signals and recording them on recording mediahave become popular. In digital cameras, memory cards using nonvolatilesemiconductor memory devices as storage media for recording digitalimage data are generally used.

An image photographed by a digital camera is printed according to thefollowing procedure: (a) removing a memory card from the memory cardslot of the digital camera, (b) inserting the removed memory card intothe PC card slot of a personal computer or the like through an adapter,and (c) sending a print instruction from the personal computer or thelike to the printer connected to the personal computer or the like,thereby printing the photographed image.

In order to eliminate such complexity in operation, a digital camera hasbeen proposed, which has a radio communication function and can directlygive a print instruction to a printer by radio communication.

In the above conventional digital camera, however, a printer to print animage, i.e., a printer to which image data is to be transmitted by radiocommunication, must be designated in advance.

Even if a printer to which image data is to be transmitted is designatedin advance, printing cannot be performed if the printer is powered offor the signal strength is small due to the specific positionalrelationship between the printer and other electronic devices. If theprinter does not exist on the radio network, printing cannot beperformed even if other printers exist on the radio network.

Furthermore, it is impossible to set a printer in advance while the useris on a trip or on the road. It is inconvenient to designate a printerevery time printing is done.

SUMMARY OF THE INVENTION

It is an object of the present invention to solve all or at least one ofthe above problems.

The present invention has been made in consideration of the abovesituation, and has as its object to provide a convenient playbackapparatus, electronic camera apparatus, and the like which can reliablytransmit image data obtained by photography to a printer existing on aradio network with simple operation and print it.

In order to achieve the above objects, there is provided a playbackapparatus which plays back image data stored in a storage medium,comprising:

a radio communication unit which constitutes a radio network, togetherwith a plurality of electronic devices, and communicates data includingthe image data;

a classification acquisition unit which acquires classifications ofelectronic devices constituting the radio network through the radiocommunication unit; and

a determination unit which determines an electronic device, with whichdata communication is to be performed through the radio communicationunit, on the basis of classification information of each electronicdevice acquired by the classification acquisition unit.

It is still another object of the present invention to easilyre-transmit image data even if communication is disconnected while theimage data is transmitted.

In order to achieve the above object, there is provided a playbackapparatus which plays back image data stored in a storage medium,comprising:

a radio communication unit which constitutes a radio network, togetherwith a plurality of electronic devices, and communicates data includingthe image data;

a classification acquisition unit which acquires classifications ofelectronic devices constituting the radio network through the radiocommunication unit;

a determination unit which determines an electronic device, with whichdata communication is to be performed through the radio communicationunit, on the basis of classification information of each electronicdevice acquired by the classification acquisition unit; and

wherein if communication with an electronic device determined by thedetermination unit with which data communication is to be performedfails while image data is being transmitted by the radio communicationunit, the determination unit determines a new electronic device withwhich data communication is to be performed.

It is still another object of the present invention to improve thelinkage between photography operation and transmitting operation orprinting operation.

In order to achieve the above object, there is provided a playbackapparatus which plays back image data stored in a storage medium,comprising:

a radio communication unit which constitutes a radio network, togetherwith a plurality of electronic devices, and communicates data includingthe image data;

a classification acquisition unit which acquires classifications ofelectronic devices constituting the radio network through the radiocommunication unit;

a determination unit which determines an electronic device, with whichdata communication is to be performed through the radio communicationunit, on the basis of classification information of each electronicdevice acquired by the classification acquisition unit;

a transmission instruction input unit which inputs an instruction totransmit image data through the radio communication unit, and atransmission control unit which performs control to transmit image datato the electronic device determined by the determination unit when aninstruction to transmit the image data is generated by the transmissioninstruction input unit; and

input unit which inputs image data, and

when the transmission instruction input unit is operated while the inputimage data is displayed for a predetermined period of time after theimage data is input, the image data is transmitted to the electronicdevice determined by the determination unit through the radiocommunication unit.

The above and other objects, features, and advantages of the presentinvention will be apparent from the following detailed description inconjunction with the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the outer appearance of the rearsurface side of an electronic camera apparatus according to the firstembodiment of the present invention;

FIG. 2 is a block diagram showing the arrangement of a digital camera100 in FIG. 1;

FIG. 3 is a view showing the form of a radio network according to thefirst embodiment;

FIG. 4 is a flow chart showing an operation procedure in the photographymode of a digital camera according to the first embodiment;

FIGS. 5A, 5B, 5C and 5D are views each showing how a list of themanufacturers and models of printers is displayed;

FIG. 6 is a perspective view showing the outer appearance of a functionexpansion apparatus for an electronic camera apparatus according to thesecond embodiment of the present invention;

FIG. 7 is a block diagram showing the arrangement of the functionexpansion apparatus for a digital camera according to the secondembodiment; and

FIG. 8 is a flow chart showing an operation procedure in the functionexpansion apparatus for the digital camera according to the secondembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiment of the present invention will be described withreference to the accompanying drawings.

First Embodiment

FIG. 1 is a perspective view showing the outer appearance of the rearsurface side of an electronic camera apparatus according to the firstembodiment of the present invention.

Referring to FIG. 1, a digital camera 100 has a lens (not shown) on itsfront surface. The digital camera 100 has, on its upper surface, ashutter button 101 for giving an instruction to take a picture, a modeselection dial 102 for setting an operation mode of the digital camera100, and a compact liquid crystal display device 103 for displaying theoperation state or the like of the digital camera 100 in characters andpictographs. An antenna 104 for radio communication is also mounted onthe upper surface.

The digital camera 100 has, on its rear surface, a color liquid crystaldisplay device 105 for displaying an object image to be photographed oran image recorded on a memory card in the playback mode, a menu button106 for invoking menu items for setting various operation conditions forthe digital camera 100, a determination button 107 for designating anitem selected from the menu items, a cross cursor button 108 for givingan instruction to select a menu item or change an operation state, andother operation buttons for designating the operation state of thedigital camera 100. In addition, the digital camera 100 has a printingbutton 109 for giving an instruction to transmit image data to a printerby radio communication.

Furthermore, the digital camera 100 has, on its rear surface, an LEDlamp 110 for displaying the operation state of the digital camera 100 orproviding alarm display and a finder for checking an object image.

A memory card cover 111 is provided on one side surface of the digitalcamera 100. The memory card cover 111 is opened by pressing a memorycard cover open lever 112 on the rear surface of the camera bodydownward, and a memory card as a storage medium is attached/detached.

An interface connector (not shown) for connecting a cable or the likefor communication with other electronic devices is provided on the otherside surface of the digital camera 100. A battery port (not shown) isformed in the lower surface of the digital camera 100 to allow a batteryto be loaded.

FIG. 2 is a block diagram showing the arrangement of the digital camera100 in FIG. 1.

The digital camera 100 includes, as its constituent elements, an imagepickup unit 201, memory card connection circuit unit 202, radiocommunication circuit unit 203, operation unit 204, display unit 205,ROM 206, CPU 207, and RAM 208. These elements are connected to eachother through a bus line 209. The digital camera 100 also has a powercircuit unit 210.

The image pickup unit 201 is roughly constituted by a lens on whichlight reflected by an object is incident, a charge-coupled device (CCD)for converting the light image formed by the lens into an electricalsignal, an analog/digital converter for converting the analog electricalsignal output from the CCD into a digital electrical signal, and thelike. The image pickup unit 201 has the function of outputting thedigital image data of the object to the bus line 209.

The memory card connection circuit unit 202 is comprised of a memorycard connection connector to which a memory card is attached and amemory card control circuit. The digital camera 100 records image dataobtained by photography on the memory card attached to the memory cardconnection connector.

The radio communication circuit unit 203 is roughly constituted by anantenna, RF circuit, encoding/decoding circuit, and the like, and hasthe function of forming a radio network, together with an electronicdevice and information processing apparatus having equivalent radiocommunication functions and transmitting and receiving data with eachother. The form of a radio network will be described later withreference to FIG. 3.

The operation unit 204 is comprised of switches and the like interlockedwith buttons, dials, and the like which are used to operate the digitalcamera 100, e.g., the photography button 101 for giving an instructionto take a picture, the mode selection dial 102 for selecting anoperation mode of the digital camera 100, and the menu button 106 forgiving an instruction to display a menu window, and has the function ofoutputting the states of these switched as electrical signals. Theoperation unit 204 also has the function of outputting a change in thestate of a switch upon operation of a button or dial as a change inelectrical signal.

The display unit 205 is comprised of the compact liquid crystal displaydevice 103, color liquid crystal display device 105, LED lamp 110, andthe like. The color liquid crystal display device 105 has the functionof displaying an image as a photography target which is formed on theCCD, and also has the function of playing back and displaying the imagedata stored in a memory card. In addition, the color liquid crystaldisplay device 105 has the function of displaying the menu window uponoperation of the menu button 106 or the like. Furthermore, the colorliquid crystal display device 105 has the function of displayingcharacter information or the like to indicate that image data is beingtransmitted by the radio communication circuit unit 203.

The LED lamp 110 displays the operation state of the digital camera andperforms alarm display for the user. In this embodiment, while the radiocommunication circuit unit 203 is transmitting image data, the LED lamp110 blinks to warn the user about the transmission.

The ROM 206 is a nonvolatile memory in which control procedures for theCPU 207 are stored in advance. The ROM 206 has the function ofoutputting stored contents to the bus line 209 in accordance with a readinstruction from the CPU 207.

The CPU 207 has the function of controlling the image pickup unit 201,controlling the memory card connection circuit unit 202, managing amemory card attached to a memory card connection connector, controllingthe radio communication circuit unit 203, detecting the switch stateoutput from the operation unit 204, and controlling the display unit 205by executing the control procedures stored in the ROM 206.

The CPU 207 also has the function of performing control to check uponoperation of the printing button 109 whether a printer exists on a radionetwork and transmit image data to the printer, if only one printerexists on the network, or to a selected one of printers if a pluralityof printers exist on the network.

Although described in detail later, upon detecting a communicationfailure during transmission of image data due to power-down of anelectronic device or disconnection of the communication, the CPU 207also performs processing to newly set a transmission destination for theimage data so as to retransmit the data.

The RAM 208 serves as a temporary buffer for the digital image dataoutput from the image pickup unit 201, a temporary storage for the datato be written on a memory card or the data read out from the memorycard, a work memory for the CPU 207, and the like. The RAM 208 has asecured area for storing the identification code of a printer as adestination to which data is to be transmitted when the printing button109 is pushed to transmit image data.

The power circuit unit 210 is roughly constituted by a battery, DC/DCconverter, and the like, and has the function of supplying power to eachconstituent element of the digital camera through a power line 211.

The radio network constituted by the digital camera according to thisembodiment and other electronic devices and information processingapparatuses will be described next.

FIG. 3 is a view showing the form of the radio network according to thisembodiment.

Referring to FIG. 3, a radio network 300 is constituted by sixelectronic devices 301 to 306 each having a radio communicationfunction.

Each of the electronic devices 301 to 306 transmits/receives a carrierwave modulated with an information signal and transmits information.Radio communication is performed by using, as a carrier wave, a radiowave that undergoes frequency-hopping of 79 frequencies set at 1-MHzintervals in the frequency range of 2.402 to 2.480 GHz at a maximum rateof 1,600 times per sec.

The radio network 300 includes the electronic device 301 serving as onemain station for performing communication control. All the electronicdevices 302 to 306 other than the main station in the radio networkserve as subsidiary stations and transmit data under the control of themain station.

The respective electronic devices 301 to 306 have their own uniqueidentification codes. In transmitting data, each subsidiary stationspecifies a distant device by transmitting the identification code of atransmission destination prior to the data under the control of the mainstation.

Note that the present invention is not limited to the form of the radionetwork described above, and can be applied to a radio network in anyform as long as the present invention can be implemented. Eachelectronic device may incorporate a circuit for implementing radiocommunication or have a radio communication unit connected externally.In addition, the type of radio waves and the form of transmission dataare not limited to those described above, and radio waves having anyfrequencies can be used. In addition, an encoding method is notspecifically limited, and it does not matter whether frequency hoppingis performed or not.

The operation of the digital camera according to this embodiment will bedescribed in detail below.

FIG. 4 is a flow chart showing an operation procedure in the photographymode of the digital camera according to the first embodiment. Note thatthe following control method can be implemented by storing a programbased on the flow chart in FIG. 4 in the ROM 206 and executing it.

When the digital camera 100 is set in the photography mode uponoperation of the mode selection dial, the CPU 207 executes the controlprocedure stored in the ROM 206 in advance, and executes the procedureshown in FIG. 4 on the way.

In step S401, the CPU 207 monitors the signal output from the operationunit 204 to check whether the photography button 101 is pushed. If YESin step S401, the flow advances to step S402. If NO in step S401, theflow advances to step S403.

In step S402, the CPU 207 transfers the digital image data obtained byphotography by the image pickup unit 201 to the RAM 208 through the busline 209 and stores it in the RAM 208, and records the image data on thememory card attached to the memory card connection connector. The flowthen advances to step S403.

In step S403, the CPU 207 monitors the signal output from the operationunit 204 to check whether the printing button 109 is pushed. If YES instep S403, the flow advances to step S404. If NO in step S403, the flowadvances to step S416.

Note that if the image is displayed on the liquid crystal display of thecamera in step S403, it helps the user determine the necessity oftransmission or printing. For this reason, after photography operation,a preview mode is preferably executed to display the photography imagefor a predetermined period of time or until the start of nextphotography. If this camera is designed to allow the user to push theprinting button 109 during execution of the preview mode, the use cancheck images. In addition, this makes it possible to link photographyoperation with print instructing operation (or transmission instructingoperation), thereby eliminating the necessity to instruct printoperation (or instruct transmission operation) while interruptingphotography operation.

In step S404, the CPU 207 checks whether any image data is stored in theRAM 208. If YES in step S404, the flow advances to step S405. If NO instep S404, the flow advances to step S406.

In step S405, the CPU 207 communicates with the respective electronicdevices constituting the radio network through the radio communicationcircuit unit 203, and makes inquiries about the classifications ofelectronic devices and the like. The flow then advances to step S407.

If it is determined in step S404 that no image data is stored in the RAM208, the CPU 207 displays, on the color liquid crystal display device105, information indicting that there is no image data to betransferred, and blinks the LED lamp 110 to perform alarm display instep S406. The flow then advances to step S416.

In step S407, the CPU 207 checks whether any printer (printingapparatus) exists among the electronic devices constituting the radionetwork, to which the CPU 207 has made inquires in step S405. If aprinter exists in the radio network 300, the flow advances to step S408.If no printer exists, the flow advances to step S409.

In step S408, the CPU 207 checks whether one or a plurality of printersexist in the radio network 300. If one printer exists, the flow advancesto step S410.

If a plurality of printers exist, the flow advances to step S411.

If it is determined in step S407 that no printer exists in the radionetwork 300, the CPU 207 displays, on the color liquid crystal displaydevice 105, information indicating that no printer exists in the radionetwork 300, and blinks the LED lamp 110 to perform alarm display instep S409. The flow then advances to step S416.

In step S410, the CPU 207 writes the identification code of the singleprinter existing in the radio network 300 in the identification codestorage area in the RAM 208. The flow then advances to step S414.

If it is determined in step S408 that a plurality of printers exist inthe radio network 300, the CPU 207 communicates with the plurality ofprinters existing in the radio network 300 through the radiocommunication circuit unit 203, and makes inquiries about the propertiesof the respective printers. The flow then advances to step S412. Notethat in this embodiment, pieces of property information about which theprinters are inquired are manufacturers and models.

In step S412, the CPU 207 displays, on the color liquid crystal displaydevice 105, a list of manufacturers and models of the respectiveprinters which are acquired in step S411, and causes the user of thedigital camera 100 to select a printer to be used for printing by usingthe cross cursor button 108 and determination button 107. The flow thenadvances to step S413. A method of selecting and determining one printerfrom a list of printers displayed on the color liquid crystal displaydevice 105 will be described later with reference to the accompanyingdrawings.

In step S413, the CPU 207 writes the identification code of the printerselected in step S412 in the identification code storage area in the RAM208. The flow then advances to step S414. In step S414, the CPU 207 setsthe identification code of the printer identification code stored in theRAM 208 in step S413 to a transfer destination address, andradio-transmits the image data stored in the RAM 208 through the radiocommunication circuit unit 203. The flow then advances to step S415. Atthis time, the CPU 207 blinks the LED lamp 110 and displays characterinformation or the like on the color liquid crystal display device 105,thereby informing the user that image data is being transmitted.

In step S415, the CPU 207 deletes the image data and the printeridentification code stored in the RAM 208. The flow then advances tostep S416. In step S416, the CPU 207 monitors the signal output from theoperation unit 204 to check whether the mode selection dial 102 is setto the photography mode or a mode other than the photography mode. Ifthe mode selection dial 102 is set to the photography mode, the flowreturns to step S401. If the mode selection dial 102 is set to a modeother than the photography mode, the operation in the photography modeis terminated.

Although not described in FIG. 4, the CPU 207 monitors, untiltransmission in step S414 is completed after steps S410 and S413,whether communication with the device to receive image data has failed.

If communication cannot be performed, the flow temporarily returns tostep S405 to automatically check whether there is any new electronicdevice that can receive image data. If only one electronic device isdetected afterward, this electronic device automatically receives theimage data.

In this case, since the camera automatically switches image datatransmission destinations, the CPU 207 displays, on the LCD 105,information indicating that the transmission destination is switched toa new one, and the specific electronic device serving as an imagetransmission destination.

With this arrangement, if a communication failure occurs when, forexample, the power supply of an image data receiving device isdisconnected, data can be smoothly transmitted to another electronicdevice.

A method of selecting one printer from a plurality of printers in stepS412 will be described below.

FIGS. 5A to 5D show how a list of manufacturers and models of printersacquired in step S411 is displayed on the color liquid crystal displaydevice 105.

FIGS. 5A to 5D show a case where four printers exist in the radionetwork 300. The user designates one printer by operating the “up”button and “down” button of the cross cursor button 108 and thedetermination button 107 while watching this display window.

If, for example, the user pushes the “down” button of the cross cursorbutton 108 three times in the display state in FIG. 5A, the displaystate of the color liquid crystal display device 105 shifts to thedisplay state shown in FIG. 5D through the display states in FIGS. 5Band 5C. If the user pushes the determination button 107 in this state,“430E” of “D company” is selected as a printer to which data is to betransmitted, and printing is performed by using this printer.

As described above, with the processed based on the flow chart of FIG.4, if one printer exists in the radio network 300, image data istransmitted to the printer to print the data. If a plurality of printersexist in the radio network 300, image data is transmitted to a selectedprinter, thus printing the data.

The first embodiment has exemplified the case where pieces of propertyinformation of which printers existing in the radio network 300 areinquired are manufacturer information and model information. However,the present invention is not limited to this. For example, the maximumresolution with which each printer can print and the number of colorsthat can be expressed by that printer can be used as pieces of propertyinformation.

In the first embodiment described above, as a method of specifying oneprinter of a plurality of printers, the method of making the user of thedigital camera select has been described above. Obviously, however, thepresent invention incorporates a method of automatically specifying aprinter on the basis of the evaluation values obtained by substitutingthe property information (e.g., maximum resolution) of each printer intoa predetermined evaluation function. If, for example, a print with highimage quality is to be obtained, a printer with the highest imagequality is always automatically selected by this method. This eliminatesthe necessity to perform cumbersome selecting operation. In addition,the trouble of disconnection of communication during transmission can beavoided by selecting an electronic device with strong radio waves.

It is convenient if a specific electronic device serving as a receptiondevice is automatically selected depending on the purpose of image datato be used (e.g., for high-quality printing or browsing on theInternet).

The first embodiment described above has exemplified the method ofdisplaying information indicating that image data is being transmitted,and performing alarm display when no image data is stored in the RAM 208and alarm display when no printer exists on the radio network 300 byblinking the LED lamp 110 or displaying character information andgraphic pattern information on the color liquid crystal display device105. Obviously, however, the present invention incorporates a method ofdisplaying information indicating that data is being transmitted andperforming alarm display by displaying characters on the compact liquidcrystal display device 103. In addition, such operation may be performedby a combination of display operation on the compact liquid crystaldisplay device 103 and display operation on the LED lamp 110 and colorliquid crystal display device 105.

Second Embodiment

The first embodiment described above has exemplified the digital camerahaving the radio communication function. However, the present inventionis not limited to the first embodiment, and can be applied to a digitalcamera to which a function expansion apparatus for expanding thefunction of the digital camera is connected. The second embodiment inwhich the present invention is applied to a function expansion apparatusfor a digital camera will be described below.

FIG. 6 is a perspective view showing the outer appearance of thefunction expansion unit for the electronic camera apparatus according tothe second embodiment of the present invention.

Referring to FIG. 6, a function expansion apparatus 600 for a digitalcamera has, on its upper surface, an antenna 601 for performing radiocommunication. The function expansion apparatus 600 has, on its sidesurface, a printing button 602 for giving an instruction to transmitdata to a printer, and an LED lamp 603 for displaying the operationstate of the function expansion apparatus 600 or performing alarmdisplay. The function expansion apparatus 600 has, on its other surface,a digital camera connection connector 604 for connection to a digitalcamera (not shown). The function expansion apparatus 600 is mechanicallycoupled and electrically connected to the digital camera (not shown)through the digital camera connection connector 604.

FIG. 7 is a block diagram showing the arrangement of the functionexpansion apparatus for the digital camera according to the secondembodiment.

The function expansion apparatus 600 has as its constituting elements aninterface circuit 701, radio communication circuit unit 702, operationunit 703, display unit 704, microcomputer 705, and RAM 706, in additionto the digital camera connection connector 604. These constitutingelements are connected to each other through a bus line 707. Thefunction expansion apparatus 600 also has a power circuit unit 708 whichis powered by the digital camera via the digital camera connectionconnector 604 and supplies power to the respective constituting elementsof the above-mentioned elements.

The digital camera connection connector 604 connects the functionexpansion apparatus 600 with the digital camera (not shown). Connectingthis digital camera connection connector 604 to the external connectionconnector of the digital camera (not shown) couples them mechanically aswell as electrically.

The interface circuit unit 701 has the function of communicating serialdata with the digital camera connected through the digital cameraconnection connector 604, and transmits/receives data to/from thedigital camera under the control of the microcomputer 705.

The radio communication circuit unit 702 is roughly constituted by anantenna, RF circuit, encoding/decoding circuit, and the like, and hasthe function of forming a radio network 300, together with an electronicdevice and information processing apparatus having equivalent radiocommunication functions and transmitting and receiving data with eachother.

The operation unit 703 is constituted by switches and the likeinterlocked with the printing button 602 for giving an instruction totransmit data to the printer, and has the function of outputting theoperation of the printing button 602 as a change in electrical signal.

The display unit 704 is constituted by the LED lamp 603 and the like andhas the function of displaying the operation state of the functionexpansion apparatus 600 and performing alarm display for the user. Inthis embodiment, the display unit 704 has the function of blinking theLED lamp 603 to inform the user that data is being transmitted when thedata is being transmitted by the radio communication circuit unit 702.In addition, the display unit 704 has the function of blinking the LEDlamp 603 to perform alarm display for the user if no image data can beacquired from the digital camera or no printer exists on the radionetwork 300 when the user pushes the printing button 602 to give aninstruction to transmit image data.

The microcomputer 705 incorporates a memory (not shown), and has thefunction of controlling the interface circuit unit 701, managingcommunication with the digital camera connected through the digitalcamera connection connector 604, controlling the radio communicationcircuit unit 702, detecting the switch state output from the operationunit 703, and controlling the operation unit 703 in accordance with thecontrol procedures stored in the memory.

The microcomputer 705 has the function of performing following controloperation. When the printing button 602 is operated, the microcomputer705 acquires image data from the connected digital camera, and checkswhether any printer exists on the radio network 300. If only one printerexists, the microcomputer 705 transmits the image data to the printer.If a plurality of printers exist on the network, the microcomputer 705transmits the image data to one of the printers.

The RAM 706 serves as a temporary storage for the image data read outfrom the digital camera through the interface circuit unit 701 anddigital camera connection connector 604, a work memory for themicrocomputer 705, and the like. The RAM 706 has a secured area forstoring the identification code of a printer as a destination to whichdata is to be transmitted when the printing button 602 is pushed totransmit image data.

The power circuit unit 708 has the function of receiving power from theconnected digital camera through the digital camera connection connector709 and supplying the power to each element of the function expansionapparatus 600 through a power line 710. The power circuit unit 708 has areset circuit, and has the following function. When the functionexpansion apparatus 600 is connected to the digital camera through thedigital camera connection connector 604 and receives power from thedigital camera, the power circuit unit 708 initializes the functionexpansion apparatus 600 by using the reset circuit.

The operation of the function expansion apparatus for the electroniccamera apparatus according to this embodiment will be described belowwith reference to FIG. 8. FIG. 8 is a flow chart showing an operationprocedure for the function expansion apparatus for the digital cameraaccording to the second embodiment. Note that the following controlmethod can be implemented by storing a program based on the flow chartof FIG. 8 in a storage unit in the microcomputer 705 and executing it.

The function expansion apparatus 600 is mounted on the digital camerathrough the digital camera connection connector 604. While the functionexpansion apparatus 600 is receiving power from the digital camera andoperating, the microcomputer 705 executes the control procedure storedin the internal memory (not shown) and repeatedly executes the procedureshown in FIG. 8 at a predetermined timing.

In step S801, the microcomputer 705 monitors the signal output from theoperation unit 703 to check whether the printing button 602 is pushed.If YES in step S801, the flow advances to step S802. If NO in step S801,this processing is terminated.

In step S802, the microcomputer 705 makes an inquiry about thepresence/absence of image data in the digital camera connected throughthe digital camera connection connector 604. If image data is present inthe digital camera, the flow advances to step S803. If no image data ispresent, the flow advances to step S804. In step S803, the microcomputer705 acquires image data from the mounted digital camera and stores thedata in the RAM 706. The flow then advances to step S805.

If it is determined in step S802 that no image data is present in thedigital camera, the microcomputer 705 blinks the LED lamp 603 to performalarm display to the user in step S804, and terminates the processing.At this time, the microcomputer 705 may inform the mounted digitalcamera of the above situation and perform alarm display by displayingthe corresponding information on the liquid crystal display unit of thedigital camera or the like.

In step S805, the microcomputer 705 communicates with the respectiveelectronic devices constituting the radio network 300 through the radiocommunication circuit unit 702 and makes inquiries about theclassifications of electronic devices or the like. The flow thenadvances to step S806. In step S806, the microcomputer 705 checks, onthe basis of the classification information of each electronic deviceabout which the inquiries were made in step S805, whether any printerexists on the radio network 300. If YES in step S806, the flow advancesto step S807. If NO in step S806, the flow advances to step S808.

In step S807, the microcomputer 705 checks whether one or a plurality ofprinters exist on the radio network 300. If one printer exists, the flowadvances to step S809. If a plurality of printers exist, the flowadvances to step S810.

If it is determined in step S806 that no printer exists on the radionetwork 300, the microcomputer 705 blinks the LED lamp 603 to performalarm display in step S808, and terminates the processing. At this time,the microcomputer 705 may inform the mounted digital camera of the abovesituation and perform alarm display by displaying the correspondinginformation on the liquid crystal display unit of the digital camera orthe like.

In step S809, the microcomputer 705 writes the identification code ofthe single printer existing on the radio network 300 in theidentification code storage area in the RAM 706. The flow then advancesto step S813.

If it is determined in step S807 that a plurality of printers exist onthe radio network 300, the microcomputer 705 communicates with therespective printers existing on the radio network 300 trough the radiocommunication circuit unit 702 and makes inquires about the propertiesof the printers in step S810. The flow then advances to step S811. Notethat in this embodiment, pieces of information about which each printerare inquired are a printable color count and maximum resolution.

In step S811, the microcomputer 705 specifies one printer to be used forprinting on the basis of the printable color count information andmaximum resolution information as the pieces of property informationabout which the inquires were made in step S810. The flow then advancesto step S812. In this embodiment, of printers with the maximum printablecolor count, a printer with the maximum resolution is specified as aprinter to be used for printing. If there are a plurality of suchprinters, an arbitrary printer is specified as a printer to be used forprinting.

In step S812, the microcomputer 705 writes the identification code ofthe printer specified in step S811 in the identification code storagearea in the RAM 706. The flow then advances to step S813. In step S813,the microcomputer 705 sets the printer identification code stored in theidentification code storage area in the RAM 706 to a transferdestination address, and radio-transmits the image data stored in theRAM 706 through the radio communication circuit unit 702, thusterminating this processing. At this time, the microcomputer 705 blinksthe LED lamp 603 to inform the user that image data is beingtransmitted.

Although not written in FIG. 8, the microcomputer 705 monitors, untiltransmission in step S813 is completed after steps S809 and S812,whether communication with the device to receive image data has failed.

If communication cannot be performed, the flow temporarily returns tostep S805 to automatically check whether there is any new electronicdevice that can receive image data. If only one electronic device isdetected afterward, this electronic device automatically receives theimage data.

As described above, by performing processing in accordance with the flowchart of FIG. 8, printing can be performed as follows. If only oneprinter exists on the radio network 300, image data is transmitted tothis printer to print. If a plurality of printers exist on the radionetwork 300, image data is transmitted to a specified printer to print.

In the second embodiment, pieces of property information about whicheach printer existing on the radio network 300 is inquired are printablecolor count information and maximum resolution information. However, thepresent invention is not limited to this. For example, as in the firstembodiment, printer manufacturer information and model information maybe used as pieces of property information.

Obviously, the present invention incorporates a method of the printerproperty information acquired in this case to the mounted digital camerato select a printer on the digital camera and receiving the selectionresult from the digital camera to specify a printer to be used forprinting.

The second embodiment has exemplified the case where serialcommunication is performed between the function expansion apparatus andthe digital camera through the connection connector. However, thepresent invention is not limited to this, and any communication schemecan be used as long as data can be transmitted. For example, an infraredcommunication scheme such as IrDA may be used.

The second embodiment has exemplified the case where display of theoperation state of the function expansion apparatus and alarm displayare performed by using the LED lamp. Obviously, however, a liquidcrystal display unit or the like may be provided for the functionexpansion apparatus to perform display of an operation state and alarmdisplay by displaying character information and graphic patterninformation.

Each embodiment described above has exemplified the digital camera.However, a digital camera may be regarded as a playback apparatus forplaying back image data stored in a storage medium such as a memorycard, and the present invention may be applied to a video playback-onlymachine having only the function of playing back image data without anyimage pickup function.

The present invention is not limited to the apparatus according to theabove embodiments and may be applied to a system constituted by aplurality of devices or an apparatus comprising a single device. Thepresent invention incorporates a control method of supplying a storagemedium storing software program codes for realizing the functions of theabove-described embodiments to a system or apparatus, and causing thecomputer (or a CPU or an MPU) of the system or apparatus to execute theabove functions in a software manner in accordance with the programcodes stored in the storage medium.

In this case, the program codes read out from the storage medium realizethe functions of the above-described embodiments by themselves, and thestorage medium storing the program codes constitutes the presentinvention. As a storage medium for supplying the program codes, a floppydisk, a hard disk, an optical disk, a magnetooptical disk, a CD-ROM, aCD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like canbe used. The functions of the above-described embodiments are realizednot only when the readout program codes are executed by the computer butalso when the OS (Operating System) running on the computer performspart or all of actual processing on the basis of the instructions of theprogram codes.

The functions of the above-described embodiments are also realized whenthe program codes read out from the storage medium are written in thememory of a function expansion board inserted into the computer or afunction expansion unit connected to the computer, and the CPU of thefunction expansion board or function expansion unit performs part or allof actual processing on the basis of the instructions of the programcodes.

As has been described in detail above, according to the presentinvention, when photography is performed by an electronic camera such asa digital camera and an instruction to print image data is issued,printing can be performed as follows. If one printing apparatus existson a radio network, the image data is transmitted to this printingapparatus to print an image. If a plurality of printing apparatusesexist on the radio network, the image data is transmitted to a selectedprinting apparatus to print an image.

With this operation, image data obtained by photography can be reliablytransmitted to a printing apparatus existing on a radio network andprinted with simple operation without designating any printing apparatusin advance.

Even if the printing apparatuses existing on the radio network changewith a change in the configuration of the radio network or the like, theproblem that printing cannot be performed can be prevented, and imagedata can be reliably printed.

The present invention is not limited to the embodiments described above,and various modifications can be made within the spirit and scopedefined in the appended claims.

1. A digital camera comprising: an image pickup unit; a photographingoperation unit which instructs the image pickup unit to start imagepickup processing; a photographing processing unit which, in accordancewith the instruction by the photographing operation unit, causes theimage pickup unit to perform the image pickup processing and storesimage data on a storage medium; a print instruction unit which instructsto print; a display unit which previews the image data obtained by theimage pickup processing, after completion of photographing by thephotographing processing unit and before a next image pickup processingthereby; and a transmission unit which transmits the image data storedon the storage medium to an external printer when the print instructionunit instructs to print during preview of the image data by the displayunit.
 2. A camera according to claim 1, further comprising: adiscrimination unit which discriminates whether an externalcommunication apparatus includes a printer, after the print instructionunit instructs to print.
 3. A camera according to claim 2, wherein thedisplay unit is arranged so as to display a warning when thediscrimination unit discriminates that the printer is not included inthe external communication apparatus.
 4. A camera according to claim 1,wherein the photographing operation unit monitors the instruction tostart the image pickup processing, after the transmission unit transmitsthe image data to the external printer.
 5. A control method for adigital camera including an image pickup unit, an image pickupinstruction unit which instructs the image pickup unit to start imagepickup processing, and a print instruction unit which instructs to printa photographed image, the control method comprising: a photographingprocessing step of, in accordance with the instruction, causing theimage pickup unit to perform the image pickup processing and storingimage data on a storage medium; a display step of previewing the imagedata obtained by the image pickup processing, after completion ofphotographing performed in the photographing processing step and beforethe next image pickup processing therein; and a transmission step oftransmitting the image data stored on the storage medium to an externalprinter in accordance with the print instruction by the printinstruction unit during preview of the image data in the display step.6. A method according to claim 5, further comprising: a discriminationstep of discriminating whether an external communication apparatusincludes a printer, after the print instruction unit instructs to printthe photographed image.
 7. A method according to claim 6, wherein thedisplay step includes a step of displaying a warning when thediscrimination step discriminates that the printer is not included inthe external communication apparatus.
 8. A method according to claim 5,wherein the photographing operation step includes a step of monitoringthe instruction to start the image pickup processing, after thetransmission step transmits the image data to the external printer.
 9. Adigital camera comprising: an image pickup instruction unit whichinstructs to start image pickup processing; an image pickup unit whichpicks up an image in accordance with the image pickup processing startinstruction by the image pickup instruction unit; and a display unitwhich previews the image picked up by the image pickup unit, after theimage pickup processing for a predetermined period of time or until thestart of a next image pickup processing, wherein if a print instructionbutton is not operated during the image preview by the display unit sothat the image pickup apparatus remains in a photographing mode, theimage pickup instruction unit is monitored to wait for the image pickupprocessing start instruction.
 10. A camera according to claim 9, furthercomprising a communication unit which communicates with an externalprinter, and a transmission unit which transmits image data to theexternal printer in accordance with the instruction provided byoperating the print instruction button.
 11. A control method for adigital camera including an image pickup unit, an image pickupinstruction unit which instructs to start image pickup processing, and aprint instruction button operative to instruct to print, the controlmethod comprising: an image pickup step of picking up an image with theimage pickup unit in accordance with the image pickup processing startinstruction by the image pickup instruction unit; and a display step ofpreviewing the image picked up in the image pickup step, after the imagepickup processing in the image pickup step for a predetermined period oftime or until the start of a next image pickup processing, wherein ifthe print instruction button is not operated during the image preview inthe display step so that the image pickup apparatus remains in aphotographing mode, the image pickup instruction unit is monitored towait for the image pickup processing start instruction.
 12. A controlmethod according to claim 11, further comprising a communication step ofcommunicating with an external printer, and a transmission step oftransmitting image data to the external printer in accordance with theinstruction provided by operating the print instruction button.